"Get down, get down, your position is not good," a rebel commander can be heard saying on an unverified YouTube video posted by fighters of the Tawheed Brigade opposing President Bashar al-Assad. "Spread out in twos and threes," the voice says. The sound of gunfire is heard. The next film purports to show the control room of the 630-megawatt Tishrin Dam following the assault, while a third displays captured military hardware including assault rifles and rocket-propelled grenades.

The rebel Free Syrian Army says it's changing tactics in the 21-month insurgency, moving from intensive combat in major cities to target infrastructure giving Assad's forces an edge, like airfields. That's driving the cost of a civil conflict estimated by the government to have caused almost $30 billion of damage. It's also forced at least 1.2 million Syrians from their homes, according to the United Nations.

Advertisement

The new approach was agreed at a series of meetings between the FSA leadership and rebel units some weeks ago, according to Bassam al-Dada, the group's political adviser, who spoke by phone Monday from close to the Turkish border. Insurgents made a mistake by occupying civilian neighborhoods like Salahuddin in Aleppo, which brought punishing retaliatory strikes resulting in large civilian casualties, he said.

"That was the wrong strategy," he said. Rebel military leaders were now guiding their fighters "toward key targets, such as military bases, airports and highways to cut means of transport for the army."

While insurgent Internet footage can't be independently verified, the government has acknowledged that major sites like Tishrin, as well as civil and military airfields including Damascus International Airport, have been the scene of heavy fighting this month and last. Rebels say they overran the Marj al-Sultan helicopter base on the outskirts of Damascus on Nov. 24, a day before the dam assault, and seized oil fields in eastern Syria in the same month.

The rebels clashed with Syrian troops today in the vicinity of Aqraba military air base, close to Damascus International Airport, Rami Abdel Rahman, head of the Syrian Observatory for Human Rights, an opposition group, said by phone from Coventry, England. The rebels have not taken the civil airport yet, he said.

Syria's government recognizes it has a problem. Prime Minister Wael al-Halaqi told ministers in a Nov. 27 Cabinet session that citizens should help authorities to guard "vital facilities," the state-run Syrian Arab News Agency reported. His list of infrastructure at risk of attack may also signal how far the rebel campaign has reached — the premier mentioned dams and highways along with oil and electricity facilities and even cereal silos.

Repeated rebel assaults on gas pipelines in Deir Ezzor, which feed treatment and power plants, forced a halt in operations at a number of generators with a total capacity of 1,500 megawatts, Minister of Electricity Imad Khamis said in a statement carried by Sana on Nov. 26. That meant that power rationing would continue as before, he said, without giving additional details.

"As Assad's forces lose more and more territory, their control over state infrastructure is also faltering," the Austin, Texas-based geopolitical consulting firm Stratfor said in a Nov. 30 report after the airport attacks and a nationwide disruption of Internet service. "The Syrian rebels don't necessarily need to take over control of the infrastructure in order to prove that Assad is weak. Putting the infrastructure in jeopardy is enough to do that."

The war is "evolving from one in which most operations focus on attacks aimed at wearing down the Syrian army and capturing weapons, to one where there is a stronger emphasis on seizing key military and infrastructural targets," said Torbjorn Soltvedt, senior analyst at Maplecroft, a British-based risk consultant. "The capture of the Tishrin Dam in northern Syria is a clear example of this."

The capabilities of Syria's disparate rebel groups have been boosted by defections from Assad's forces and foreign fighters who "are playing an important role in improving strategy and tactics," Ozgur Unluhisarcikli, director of the German Marshall Fund of the United States in Ankara, said in e- mailed comments.

In recent weeks, rebels claim to have captured air force bases, including the al-Mintar base outside Aleppo, closed major highways, shot down fighter jets and helicopter gunships and attacked government buildings, such as the agricultural research center in Aleppo.

The Syrian army too has evolved, using firepower from its arsenal of advanced weaponry, including artillery pieces, tanks, combat aircraft and attack helicopters. And it has held onto the capital Damascus even as the fighters say they've taken control of some pockets around it. Opposition groups like the Local Coordination Committees daily report government bombardment of rebel-held areas in and around Damascus. An average of 150 deaths a day are reported by opposition groups like the Syrian Observatory.

"We can't say that the Syrian military is finished," said Oytun Orhan, an analyst at the Center for Middle Eastern Strategic Studies in Ankara. "The rebels might have learned guerrilla war in cities, but the Syrian regime still has a strong army with tanks and fighter jets and as long as the regime can defend Damascus, it will survive."